Chinese police have seized the remaining suspects sought for the massacre of 29 people in Kunming this weekend, state media announced on Monday.

"Of an eight-member group (six men, two women), four were shot dead by police at the scene, a wounded woman was arrested and the other three have been captured," said the official Xinhua news agency. It cited a statement from the Ministry of Public Security, which identified the leader of the gang as Abdurehim Kurban.

Previous reports said more than 10 people were involved. No explanation of the discrepancy was given.

Saturday's attacks at the city's train station also saw 143 people injured, as the assailants hacked and slashed at people apparently at random.

Earlier on Monday, a state newspaper warned that China must adopt expensive and controversial measures to prevent further terrorist attacks.

"To guard against the terrorists from East Turkestan [Xinjiang] doing evil things, we must introduce additional measures for Chinese society outside Xinjiang. It is expensive, necessary and especially sensitive, and it will bring a series of inconveniences, and result in some controversy," said the editorial in the Global Times.

It warned that Uighurs – the Turkic-speaking ethnic minority from Xinjiang – in particular should "understand and tolerate some inconvenience" and urged others in China to maintain harmonious relations with Uighurs, rather than playing into the hands of terrorists seeking to split society.

The newspaper is state-run, although it does not represent the official voice of authorities. The piece was titled: "Let East Turkestan scum suffer the state's iron fists – the more fiercely they attack, the faster they die."

Xinjiang has seen repeated outbreaks of violence amid friction between authorities and members of the Uighur minority, many of whom complain that their religion and culture are suppressed. In 2009, almost 200 died in riots in the capital of the north-western region, as Uighurs attacked Han Chinese and other ethnic groups, and Han launched revenge attacks on Uighurs.

So far it appears that the incident in Kunming, capital of Yunnan province, will echo previous attempts to counter Xinjiang-related violence: tougher security measures coupled with accelerated economic development. Some believe that the strategy has backfired.

Yu Zhengsheng, one of the country's top leaders, told the opening session of a political advisory body in Beijing on Monday that China would boost development and industrialisation in ethnic-minority areas to increase unity and harmony, although he did not explicitly link the comments to the Kunming incident.

Professor Rohan Gunaratna, head of the international centre for political violence and terrorism research at Nanyang Technological University in Singapore, said the killings were the natural progression of a growing terrorist threat within Xinjiang, as perpetrators sought to increase their impact.

Gunaratna said the last year had seen 200 terrorist incidents in Xinjiang. Others query that figure but agree that unrest has increased sharply.

China has poured growing sums into security in Xinjiang, but Gunaratna said it needed to build a robust security and high-quality intelligence system both inside and outside the region – meaning that it should not overreact and adopt harsh measures.

"It's only through engagement that China can improve intelligence. [This attack] demonstrates the real need for China to work with the Uighur community, because most do not support terrorism," he said.

Analysts differ on the extent to which unrest in Xinjiang is co-ordinated or arises from small groups acting individually; and to the extent of its links to overseas groups. There is particular disagreement on whether the East Turkestan Islamic Movement (ETIM)_ – frequently blamed for violence – is, or was, a significant and sophisticated organisation.

But a growing number believe that foreign influences have become more important. Gunaratna suggested that political violence had become politico-religious thanks to the impact of the Taliban and al-Qaida. He argued that some attacks were caused or led by ETIM while others were inspired or instigated by the group.

Nicholas Bequelin, at Human Rights Watch, suggested the upsurge in violence reflected in part the spread of information on foreign jihadist movements via the internet, offering an ideology to those who were disgruntled and disenfranchised for reasons relating to ethnicity.

"Radical Islam around the world is the grammar of oppression in Muslim society," he said.

Li Wei, director of the anti-terrorism study centre at the China Institutes of Contemporary International Relations, said he did not believe the motivation for the Kunming attack was religious, but political.

He added that the public needed to be better educated about the escalating terrorist threat.

The New York Times reported that one local police station in Nanning – the capital of Guangxi, which borders Yunnan province – urged citizens to report anyone from Xinjiang "living, doing business or travelling here" so officers could investigate.

An officer at Xiangu police station said it was intensifying management and control but that the detention of four Uighur "escaping criminals" on Monday was not related to the Kunming attack.